Federal attorneys told a San Diego judge Tuesday that officials have by now reunited 1,012 migrant families separated at the southern border in recent months.

The government has a Thursday court-ordered deadline to return more than 2,500 migrant children to their parents. But hundreds of parents may have already been deported without their kids, according to court documents.

U.S. District Judge Dana Sabraw pressed officials to provide lists of parents who’ve been deported, those released from immigration custody, and parents who according to the government waived their right to be reunified with their kids before being removed from the country.

Officials would not say how many of the reunited families have been released. Another hearing is set for Friday.